I have made an online tool to translate colors from a photo to acrylic and oil color mixes.This program let's you work with confidence in all light conditions. You can use it for extremely precise mixes but also just to help inspiring you with which pigments to use.

Hi, I personally can recommend another color tool for designers - color picker. It's a simple program - simply point to a color and it will tell you the hex. It is Pixie by Nattyware. It works on many platfoms and is free. I hope it will be useful for you